The preparation of insoluble humic acid and its adsorption capacity

Abstract:

The humic acid which is extracted from Huangling, Shaanxi province is used as material. The temperature and the holding time are selected as variables. The insoluble humic acids under different conditions are prepared by high temperature dehydration calcification method. The experimental results show that the adsorption effect is the best when the modified humic acid holding time is 2 h and the holding temperature is 330 ℃. Under the optimum conditions, the adsorption amount of insoluble humic acid on Cu2+ ions in water is 8.87 mg/g and the adsorption rate of methylene blue is 98.8%.The iodine adsorption value of humic acid is 158.4 mg/g. The insoluble humic acid BET (the abbreviation of three scientists whose name are Brunauer、Emmett and Teller) surface area and microporous adsorption capacity under the best preparation condition are increased, so the iodine adsorption value of insoluble humic acid is 262.9 mg/g. SEM analysis shows that the surface of insoluble humic acid is rougher and is loaded with many spherical small particles, which could improve the adsorption capacity obviously. FTIR analysis shows that the contents of hydroxyl and organic halides in the insoluble humic acid structure are increased obviously. It is beneficial to the adsorption of heavy metal ions and organic pollutants.